The invention relates to xcex2-peptides, or peptides including P-amino acids, particularly xcex2-peptides that exhibit antibacterial properties. The present invention also relates to materials that incorporate the peptides, thereby providing the materials with antibacterial properties.
Most proteins typically found in nature are made up of xcex1-amino acids. In a-amino acids, the amino group is attached to the molecule at the xcex1-carbon atom. The amino group may also be attached to other carbon atoms. For example, in xcex2-amino acids and gamma-amino acids, the amino group may be attached to other carbon atoms.
Incorporation of different amino acid forms can result in differences in the structure of proteins that incorporate the amino acids. In a protein that incorporates xcex2-amino acids, the amino group of the amino acid is still bonded to the carboxylic acid group of an adjacent amino acid, forming an amide bond. When xcex2-amino acids are joined to form a protein, an extra carbon atom will be present in the chain of carbon atoms formed in the protein.
Proteins can have primary, secondary, tertiary and quaternary structures. The function of a protein may be related to its structure since the structure may permit the protein to interact with other molecules or structures. For example, having a certain sequence of amino acids that fold in a certain manner, a protein may have a complementary structure to another molecule or portion of a cell structure, thereby permitting the protein to interact with other molecules or cells. Changing the arrangement of the atoms in the amino acids, as with xcex2-amino acids, and, subsequently, changing a protein or peptide does not alter the nature of the atoms and, for example, charges associated with the atoms.
The present invention provides particular xcex2-peptides that have antibacterial properties. The antibacterial xcex2-peptide can have the following formula: 
wherein
R1 is H, an alkyl group including 1-4 carbon atoms, phenyl, heteroaryl, or an alkyl-aryl;
R2 is an amine-containing alkyl group having the formula xe2x80x94(CH2)mNH2, wherein m=1, 2, 3, 4, or 5, (CH2)xNHCxe2x95x90NHNH2 wherein x is 1, 2, 3, 4, or 5, a pyridyl, an alkylpryidyl, an amidine-substituted benzyl, a phenyl group, or a cyclic amidine;
R3 is H, an alkyl group including 1-4 carbon atoms, phenyl, heteroaryl, or an alkyl-aryl;
X is xe2x80x94NH2, xe2x80x94OH, xe2x80x94NHR, or OR where R is alkyl, aryl or acyl groups either free or polymer-supported, a carboxamide, a substituted carboxamide, or a polymer;
Y is H, an alkyl group, an acyl group, an acyl-terminated polymer, a sulphonamide, an ether, a urea, a urethane, or a polymer; and
n is 2, 3, 4, 5, 6, or 7.
Additionally, the present invention provides antibacterial P-peptides having the following formula:
Yxe2x80x94(T)nxe2x80x94X 
wherein
n is 2, 3, 4, 5, 6, or 7;
X is xe2x80x94NH2, xe2x80x94OH, xe2x80x94NHR, or OR where R is alkyl, aryl or acyl groups either free or polymer-supported, a carboxamide, a substituted carboxamide, or a polymer;
Y is H, an alkyl group, an acyl group, an acyl-terminated polymer, a sulphonamide, an ether, a urea, a urethane, or a polymer; and
T is a triplet including T1-T2-T3, wherein T1 comprises a hydrophobic xcex2-amino acid, T2 comprises a polar or basic amino acid, T3 comprises either a hydrophobic xcex2-amino acid or a polar or basic xcex2-amino acid, wherein at least one-half of the triplets include a basic xcex2-amino acid.
Significanly, the present invention concerns a number of applications of these xcex2-peptides to provide antibacterial properties when incorporated into other materials.
Still other objects and advantages of the present invention will become readily apparent by those skilled in the art from a review of the following detailed description. The detailed description shows and describes preferred embodiments of the invention, simply by way of illustration of the best mode contemplated of carrying out the present invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, without departing from the invention. Accordingly, the drawings and description are illustrative in nature and not restrictive.